Doctor for paper-making machines



July, 27,1925.

2 Sheets-Sheet '1 9,- dZM F W VICKERY DOCTOR FOR PAPER MAKING MACHINES Flled March 23, 1926 July 27 192.6. 1,594,284

- F. W. VICKERY I DOCTOR FOR PAPER MAKING MACHINES Filed March-25 1926 2 Sheets-Sheet 2 Patented July 27, 1926.

UNITED; STATES PATENT OFFICE.

FREDERICK WILLIAM VICKERY, OF LONDON, ENGLAND, ASSIGNOR TO VICKERY LIM- ITED (INCORPORATED), OF BOSTON, MASSACHUSETTS, A CORPORATION.

DOCTOR FOR PAPER-MAKING MACHINES.

Application filed March 23, 1926. Serial No. 96,844.

This invention relates to doctors for rolls which come in contact with fluid or semifluid materials from which they must afterwards be cleansed, such as the rolls of papermaking and like machines, the ink rolls of printing machines and so forth, all of which machines are herein referred to as paper making machines. Its purpose is the provision of a doctor that will so closely bed to upon the roll as to be effective in removing water or other liquid as well as solid matter from it, and that will deliver the water so removed at the sides of the machine, that is to say at the ends of the doctor.

A doctor according to the invention comprises a flexible doctor blade of such nature and so supported that its edge will remain closely applied to a roll throughout its length in spite of irregularities in the surmy face or radius of the roll, in combination with a seal or packing making a watertight joint with said blade throughout its length, so as to force the water removed from the roll to escape longitudinally of the w doctor blade to the sides of the machine.

To secure the desired close contact between the doctor blade and the roll the doctor blade must not only be flexible but also it must be supported from the rigid doctor carrier by resilient means which permit it to move relatively to the carrier in following the inequalities or irregularities of the roll. The invention may be viewed as the combination with a doctor blade so supported of means making a water-tight joint between the blade and the carrier.

A complete doctor ready for attachment to an existing machine will usually comprise a stiff doctor carrier adapted to be secured transversely of the machine adjacent a roll, a continuous flexible doctor blade resiliently supported from said carrier, and a packing strip also carried from said carrier in contact with saidblade throughout the 15 greater part of its length.

In new machines the usual pivoted doctor carriage may be modified to support a flexible doctor blade resiliently and to permit of a Water-tight joint being made between the blade and'the carriage.

Examples of construction of the invention are illustrated in the accompanying drawings of which- Figure 1 shows the new doctor as applied to an existing machine to replace the wooden doctor blade hitherto usual.

Figure 2 is a modified construction of doctor, also adapted to be applied to existing machines, and r Figure 3, is a suitable construction of doctor for a new machine.

In Figure 1, 1 is part of the surface of one of the rolls of a paper making machine. 2 is the usual doctor carriage to which the wooden doctor blade was formerly attached. This carriage extends across the full width of the machine and is pivoted, the pivot not appearing in the drawing.

The new doctor comprises a stiff carrier adapted to be attached to the existing carriage, and a. flexible doctor blade 8 supported from the carrier by resilient means 9. In the structure shown the carrier is built up of a bar 6 and a stifl plate 10 which with the bar 6 is fastened upon the carriage 2 by set screws 7. The resilient means 9 may be a thin bronze plate, but I prefer to employ a large number of parallel spring fingers each attached to the plate 10 by a screw 11 with a distance piece 12 inserted between. The

blade 8 is a continuous strip of material thin enough to be flexible both lengthwise and torsionally. It is carried upon the fingers 9 by studs 13 which permit the blade a free lengthwise movement limited in any suitable manner. Furthei' details of asuitable construction of doctor blade and resilient support may be found in my Patent No. 1,552,363.

The plate 10 extends over the fingers beyond the edge of the blade 8 and there carries a packing strip 14, for instance a strip of rubber attached to it by studs 15. The strip is recessed upon its under side so as to form a very flexible lip which will make a close joint with the surface of the blade 8.

A water-tight joint should also be made at 16 between the bar 6 and the carriage 2. There is then no possibility of leakage of water on to the paper web beneath however far the water or wet material removed from the roll by the doctor. may accumulate upon the' carrier and carriage. The water is forced to move lengthwise of the doctor and escape at the sides of the machine where suitable provision may be made for its collection and removal. The doctor, or preferably both doctor and doctor carrier or doctor carriage may be slightly inclined towards one or both sides to assist the flow.

The carriage 2 is of such. weight or is so loaded as to apply the necessary pressure to the edge of the doctor blade. The thickness of the packing strip 14 and the yield of the resilient attachment 9 under the pressure of the blade upon the roller must be such as to bed the blade firmly enough on the packing strip to make a water-tight joint.

In case the carriage 2 should become overloaded by accumulation upon it of material removed by the doctor, or in case it should be unnecessarily heavy, set screws 3 secured by lock nuts 4 in frame members 5 projecting, for instance, from the bearings of the roll 1, form stops on which the carriage can rest.

Figure 2 shows a doctor blade 17 of wood. Its efi'ective thickness is reduced and its flexibility assured by a considerable number of bores such as 18, some of which, for instance alternate bores, are filled with metal dowels'to stiffen the blade transversely and prevent its permanent deformation. The blade rests upon aplate 19 fastened to the two-part carrier 20, and is-pressed upon the roll by spring fingers 21. Screws 22 serve to fasten together the parts of the carrier and to attach the plate 19 and fingers 21. To make a water-tight joint between the doctor blade and carrier the rear edge of the blade is sheathed in rubber as at 23, this sheathing bedding upon the plate 19 under the pressure of the fingers 21, and ulpon the carrier 20 under the frictional t rust of the roll upon the doctor blade. Packing 24 may be provided to make a water-tight joint between the parts of the carrier and between the carrier and plate 19.

Figure 3 is generally similar to Figure 1 save only that the carrier and carriage are integral. The resilient support 9 is fastened beneath the carriage 25 which has a ilate-like extension 26 reaching over the lade 8. The packing strip 14 is not attached to the carriage but is gripped between it and the blade 8, being positioned by a rabbet 27 on the carriage.

What I claim is 1. The combination with a roll ofa doctor carrier substantially parallel with the roll, a flexible doctor blade contacting with the roll, resilient means interposed between said blade and said carrier permitting said blade to conform to irregularities of said roll, and meansmaking a water-tight joint be tween said blade and said carrier.

2. A doctor for the rolls of paper-making machines comprising a stiff doctor carrier, a doctor blade, and means supporting said doctor blade from said carrier permitting said blade longitudinal and transverse movement with respect to said carrier and making a water-tight joint between said blade and said carrier.

3. A doctor comprising a stiff bar, a plurality of spring members attached to said bar, a flexible doctor blade carried in said spring members, and a packing strip making a watertight joint between said doctor blade and said bar.

l-. In a paper-making machine the combination with a roll of a flexible doctor blade having one edge bearing on said roll, a doctor carrier extending over the other edge of said blade on the opposite side from said 'roll, resilient means supporting said blade from said carrier Without preventing relative longitudinal movement, and a packing strip inserted and filling the space between the overlapping parts of said blade and carrier.

5. In a paper-making machine the combination with a roll and a doctor carriage of a flexible doctor blade having one edge bearing on, said roll, a stiff plate making joint with said carriage and extending over the other edge of said blade, spring means beneath said plate'pressing said blade upon the roll, and a packing strip held between said blade and said plate.

6. In a paper-making machine the combination with a roll of a flexible blade, a rigid bar, means resiliently supporting said blade from said bar, and a packing strip contacting with said blade and making a water- 'rght joint with it.

7. In apaper-making machine the combination with a roll of a flexible blade bearing at one edge upon said roll, spring means bearing against said blade at the other edge and on the same side thereof as said roll, and a packing strip bearin on the opposite side of said blade intermediate its width. 8. doctor for a paper-makin machine comprising a rigid'bar adapted to e mounttransversely of such machine, a flexible doctor blade carried upon said bar so that its free edge can move resiliently with respect to said bar, and packing means firmly supported by said bar in position to make joint with said blade throughout its length.

9. A doctor for a paper-making machine comprising arigid bar, parallel spring fingcrs carried by said bar, a continuous doctor blade supported on said fingers but ca able of limited longitudinal movement wit respect thereto, and means making a water tight joint between said bar and said doctor blade.

10. In a paperemaking machine the combination with a roll of a rigid bar substantially parallel with said roll, spring fingers attached to said bar, a continuous flexible blade carried in the ends of said fingers, a

rigid plate attached to said bar and extending over said blade, and means making a water-tight joint between said plate and said blade.

11. In a paper-making machine the combination with a roll of a rigid bar substantially parallel with said roll, spring fingers attached to said bar, a continuous flexible blade carried in the ends of said fingers, a rigid plate attached to said bar and extending over said blade, and a rubber strip attached to said plate said blade.

In testimony whereof I have signed my name to this specification.

FREDERICK WILLIAM VICKERY.

and making joint with 15 

